'bankerdom' originates from English, specifically the word 'banker' + the suffix '-dom', where 'banker' ultimately comes from Italian 'banchiere' (from 'banco' meaning 'bench') and the suffix '-dom' comes from Old English 'dōm' meaning 'state, condition, judgment'.

'banker' developed from Italian 'banchiere' via Late Middle English and early Modern English as 'bank' came to mean a financial bench/institution; the Old English suffix 'dōm' produced nouns denoting a state or domain (e.g. 'kingdom'); the modern compound 'bankerdom' was formed in Modern English by combining 'banker' + '-dom'.

Originally 'banco' referred to a physical bench and 'banker' a person at that bench; over time 'bank' became the financial institution and related terms shifted to denote institutional or social domains; 'bankerdom' came to mean the realm or influence of bankers rather than a literal bench.